Efficacy of scalp nerve blocks using ropivacaïne 0,75% associated with intravenous dexamethasone for postoperative pain relief in craniotomies.

ABSTRACT

Pain after supratentorial craniotomy is common, 55 % to 80 % of patients experience moderate to severe pain in the first 48 h(1-7). The importance of intravenous dexamethasone as an adjuvant to local anaesthetics is increasingly applied(1-7), however its role in scalp nerve blocks with ropivacaine 0.75 % remains unexplored in post-operative analgesia. We analyzed 134 supratentorial craniotomies under general anaesthesia, 46 of which had preoperatively bilateral scalp nerve blocks with ropivacaine 0.75 %. The general anaesthesia was standardized and included 8 mg of intravenous dexamethasone at the induction. The postoperative pain was assessed using the numerical rating scale with patients in the post anaesthesia care unit and subsequently every 8 h in the neurosurgery unit until the 48th hour. A NRS value above 3 led to the administration of a rescue analgesic according to the defined protocol until an efficient analgesia was obtained. Postoperative pain was controlled in both groups, however the need for rescue analgesics in the scalp nerve blocks group was reduced by 40 % (39 % vs. 65 %; p = 0.006) compared to the control group. More than 60 % of the patients from the scalp nerve blocks group had an efficient analgesia without any rescue analgesic. Peroperatively the scalp nerve blocks group showed a decrease in opioid consumption and a better hemodynamic stability. No anesthetic or chirurgical complications related to the use of scalp blocks were observed. Scalp nerve blocks associated with intravenous dexamethasone are found to be a straightforward and efficient analgesic approach during supratentorial craniotomies.